textproduct: Rapid City

KEY MESSAGES

- Rain and snow showers continue through Monday afternoon, heaviest precipitation favored across south-central South Dakota.

- Cooler, unsettled weather continues through next week, with a gradual warming trend towards the end of the week.

DISCUSSION

(This Evening Through Sunday) Issued at 1234 PM MDT Sun Apr 26 2026

Current upper-air analysis and water vapor imagery depict the lingering upper low over central SK/MB, with multiple shortwaves embedded southwest of the low and a second low positioned over UT/CO. WV imagery indicates increasing low-level cloud cover moving in from NE/WY, along with expanding rain and snow showers over portions of southwest and central SD (per regional radar loop and webcams). Current surface observations show temperatures in the 30s and 40s with east/southeast winds, gusting to 20 to 30 mph.

The upper low over central Canada begins to shift northeast this afternoon/evening, allowing the second surface-low to move off the Rockies and into the Great Plains. This second low will be the driving factor for the location and duration of precipitation for today and into Monday across the CWA. Current model runs place the low over CO, progressing northeast through Sunday and Monday before exiting the region Monday night. Current ensemble guidance suggests rain and snow will occur on and off through the remainder of today and into Monday morning, with the heaviest precip rates between 18Z and 00Z this afternoon and again between 06Z and 12Z Monday. Some uncertainty remains regarding exact QPF totals due to disagreement between ensembles/models (e.g. NBM, HREF, ECMWF). Even with this uncertainty, the highest QPF amounts are still expected over south- central SD, where at least 0.75" of liquid remains possible (65 to 75% chance, NBM-CONUS). Southwestern SD and the Black Hills may still receive at least 0.5" of liquid (55 to 75% chance, NBM-CONUS), with lower amounts over northwester SD and northeastern WY. Higher elevations of the Black Hills may receive 1 to 3 inches of snow, while 1 to 2 inches are possible across portions of northeast WY through Monday morning. As the pressure gradient strengthens on the back side of the surface-low Monday afternoon, gusty northerly winds (35 to 45 mph) will develop over the SD plains east of the Black Hills.

As the surface-low departs, drier but still unsettled conditions are expected through the rest of the week. Another disturbance will move through late Monday night into Tuesday, increasing precipitation chances. Near-average temperatures are expected the rest of the week, with highs mainly in the 50s and 60s after Monday.

AVIATION

(For the 18Z TAFS Through 18Z Monday) Issued At 1111 AM MDT Sun Apr 26 2026

Band of rain/snow showers has developed from southwestern SD through central SD, with MVFR/IFR conditions. This band of showers should arrive at KRAP between 18-1820z with IFR conditions. Widespread MVFR/IFR conditions will overspread the region through the afternoon and evening with low clouds and fog, in addition to rain and snow showers. Transient LIFR conditions possible overnight in fog.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.